Impact on Breast Cancer Survival by Surgical Facility Type Secondary to the ACOSOG Z0011 Trial

Studies have reported differences between age, socioeconomic status, treatment facility, and tumor burden based on survival outcomes for breast cancer (BC). The goal of this study is to evaluate BC survival and mortality outcomes by facility type. To examine likely influence of evidence-based practices, these groups were then sub stratified by pre- and post-Z0011 trial.

This is a population-based study using the National Cancer Database of Commission on Cancer (CoC) designated centers. Intergroup comparisons of demographics were performed using chi-square test. Kaplan-Meier curve and Cox Hazard Ratios were used to evaluate survival differences. Multivariable regression methods were used to evaluate risk-adjusted 30- and 90-day mortality among BC patients. A difference-in-difference (DiD) analysis was used to evaluate the change of treatment over time pre- and post-Z0011 trial.

Median survival was highest among comprehensive community facilities at 63.2 months and integrated community facilities at 62.7 months, while the lowest for community and academic facilities at 60.6 months and 61 months. Academic facilities had the lowest 30- and 90-day mortality. Community centers saw the largest improvement in overall mortality post-Z0011 trial. The benefit after the Z0011 trial was evident among community centers at the 90-day mortality period as their decrease in mortality (-1.7%) was significantly lower than the decrease of mortality among academic centers (-1.3%), P-value = .01.

While the Z0011 trial had a positive influence in both community and academic facilities, community programs benefited the most. Z0011 trial showed the most change in practice for the community centers.